<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>登录页面</title>
<link rel="stylesheet" href="../style/style.css">
<link rel="stylesheet" href="../fontawesome/css/all.min.css">
<link rel="stylesheet" type="text/css" href="../layui/css/layui.css" />
<script src="../js/jquery-3.6.1.js"></script>
</head>
<!-- 209000740 柳胜酉  -->
<script type="text/javascript">
	var flag=${flag};
	if(flag==1){
		alert("请重新输入！");
	}else if(flag==2){
		alert("用户名或密码有误！");
	}
</script>

<body>
	<div class="container">
		<div class="header">
			<h2>云彩新闻网</h2>
			<h1>用户登录</h1>
		</div>
		<div class="main">
			<form action="${pageContext.request.contextPath }/login"
				method="post">
				<span class="out"> <span class="inside">用户名</span> <input
					class="input-in" type="text" name="username">
				</span><br> <span class="out"> <span class="inside">密码</span> <input
					class="input-in" type="password" name="password">
				</span><br> <span class="decrib">验证码：</span> <input class="input-val"
					type="text" placeholder="请输入验证码">
				<canvas id="canvas">
                </canvas>
				<br>

				<button id="login" type="submit">立即登录</button>
				<br> <span class="out"> <a
					href="${pageContext.request.contextPath}/showNews">切换至新闻首页</a><br>
					<a class="agree"
					href="${pageContext.request.contextPath}/jsp/register.jsp">
						还没有账号，点击注册</a>
				</span>

			</form>
		</div>
	</div>

	<!--
验证码
作者：柳胜酉
时间：2022-12-08
描述：验证码部分代码
-->
	<script>
        $(function () {
            var show_num = [];
            draw(show_num);

            $("#canvas").on('click', function () {
                draw(show_num);
            })

            //单击事件的时候校验输入的验证码是否正确
            $("#login").on('click', function () {
                var val = $(".input-val").val().toLowerCase();
                var num = show_num.join("");
                if (val == '') {
                    alert('请输入验证码！');
                } else {
                    alert('验证码错误！请重新输入！');
                    $("#login").val('');
                    draw(show_num);
                }
            })
        })


        function draw(show_num) { //显示区域内容信息
            var canvas_width = $('#canvas').width();
            var canvas_height = $('#canvas').height();
            var canvas = document.getElementById("canvas"); //获取到canvas的对象，演员
            var context = canvas.getContext("2d"); //获取到canvas画图的环境，演员表演的舞台
            canvas.width = canvas_width;
            canvas.height = canvas_height;
            var sCode =
                "a,b,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0";
            var aCode = sCode.split(",");
            var aLength = aCode.length; //获取到数组的长度

            for (var i = 0; i <= 3; i++) {
                var j = Math.floor(Math.random() * aLength); //获取到随机的索引值
                var deg = Math.random() * 30 * Math.PI / 180; // 产生0~30之间的随机弧度
                var txt = aCode[j]; //得到随机的一个内容
                show_num[i] = txt.toLowerCase();
                var x = 10 + i * 20; //文字在canvas上的x坐标
                var y = 20 + Math.random() * 8; //文字在canvas上的y坐标
                context.font = "bold 23px 微软雅黑";

                context.translate(x, y);
                context.rotate(deg);

                context.fillStyle = randomColor();
                context.fillText(txt, 0, 0);

                context.rotate(-deg);
                context.translate(-x, -y);
            }
            for (var i = 0; i <= 5; i++) { //验证码上显示线条
                context.strokeStyle = randomColor();
                context.beginPath();
                context.moveTo(Math.random() * canvas_width, Math.random() * canvas_height);
                context.lineTo(Math.random() * canvas_width, Math.random() * canvas_height);
                context.stroke();
            }
            for (var i = 0; i <= 30; i++) { //验证码上显示小点
                context.strokeStyle = randomColor();
                context.beginPath();
                var x = Math.random() * canvas_width;
                var y = Math.random() * canvas_height;
                context.moveTo(x, y);
                context.lineTo(x + 1, y + 1);
                context.stroke();
            }
        }

        function randomColor() { //得到随机的颜色值
            var r = Math.floor(Math.random() * 256);
            var g = Math.floor(Math.random() * 256);
            var b = Math.floor(Math.random() * 256);
            return "rgb(" + r + "," + g + "," + b + ")";
        }
    </script>
</body>

</html>